I only do a handful every now and then. Sometimes I will get a bunch and run through them on a rainy day. It's pretty hit and miss (key word MISS).

If you notice ONE note always looks in great shape, one you would keep. The other is usually not BUT matches the serial number. So I keep both. Otherwise I would never keep the 2nd one.

I spent a LOT of money to have a custom program written for me that allows me to do exotic stuff and keep lots of information. I try to enter all the data upon note acquisition, if they pile up it is a PAIN to enter.

I can enter 'fish' and all the notes with fish come up. Or a string of variables, like a note I cannot remember but it is "Asian" w/ a "Fish" and a "Woman" on it, the results are just a few possibilities I can browse and fing the note from many thousands. It comes in handy sometimes.

Also, as I learn new things, I add the information to the database.

That data gets BACKED UP Daily! I would be SICK to lose it. God knows how many HOURS I have put into it.